Department of Pathology, Laboratory Medicine Programme, University Health Network/University of Toronto, Toronto, Canada.
Am J Surg Pathol. 2010 Mar;34(3):401-4. doi: 10.1097/PAS.0b013e3181ce9204.
The so-called clear cell change has been described in neuroendocrine tumors at several locations. Those associated with von Hippel Lindau disease are pathognomonically "clear" and the cytoplasmic appearance has been ascribed to intracytoplasmic lipid. However, lipid has not been demonstrated in all cases of clear cell carcinoid tumors. Such variants have not been described in carcinoid tumors of the appendix and cases with a prominent proportion of clear or more correctly, lipid-rich cytoplasm may bear a superficial resemblance to goblet cell carcinoid and/or signet ring adenocarcinoma. Seven cases, in 5 females and 2 males ranging in age from 22 to 65 years, were noted to have a population of lipid-rich and vacuolated clear cells accounting for 25% or more of the tumor population. The carcinoid tumors were incidental in all cases with 4 of patients presenting with appendicitis, 2 with concomitant mucinous cystadenocarcinomas of the appendix and 1 with an adenocarcinoma of the ascending colon. Morphologically, the tumors had a nested and trabecular pattern and were composed of an admixture of microvesicular and clear lipid-rich cells. There were no mitoses, areas of necrosis of lymphovascular invasion and all cases extended to the mesoappendix. All cases were positive for synaptophysin, chromogranin, and serotonin but negative for inhibin. Three cases were examined ultrastructurally, and showed the presence of intracytoplasmic lipid and neurosecretory granules. None of the patients have shown evidence of recurrent disease. The importance of recognizing this variant of carcinoid tumor in the appendix is to avoid confusion with goblet cell carcinoid tumors with or without a signet ring adenocarcinoma. The presence of multi-vacuolated, foamy and clear cells, some resembling signet ring or goblet cells, in otherwise classic carcinoid tumors is rare but should be considered in this context in the appendix.
所谓的透明细胞改变已在多个部位的神经内分泌肿瘤中描述。那些与 von Hippel Lindau 病相关的肿瘤具有特征性的“透明”细胞质外观，其细胞质外观归因于细胞内脂质。然而，并非所有透明细胞类癌肿瘤病例中都能发现脂质。在阑尾类癌肿瘤中尚未描述此类变体，并且具有大量透明或更确切地说富含脂质的细胞质的病例可能与杯状细胞类癌和/或印戒细胞腺癌具有表面相似性。在 5 名女性和 2 名男性中，年龄为 22 至 65 岁，共发现 7 例肿瘤细胞中存在富含脂质的空泡透明细胞，占肿瘤细胞的 25%或更多。所有病例均为偶发肿瘤，其中 4 例伴有阑尾炎，2 例伴有阑尾黏液性囊腺癌，1 例伴有升结肠癌腺癌。形态上，肿瘤具有巢状和小梁状模式，由微泡和富含透明脂质的混合细胞组成。没有有丝分裂、坏死区、淋巴血管浸润，所有病例均延伸至阑尾系膜。所有病例均对突触素、嗜铬粒蛋白和血清素呈阳性，但对抑制素呈阴性。3 例进行了超微结构检查，显示存在细胞内脂质和神经分泌颗粒。所有患者均未出现疾病复发的证据。认识阑尾中这种类癌肿瘤变体的重要性在于避免与具有或不具有印戒细胞腺癌的杯状细胞类癌混淆。在其他方面经典的类癌肿瘤中，存在多泡状、泡沫状和透明细胞，有些类似于印戒细胞或杯状细胞，这种情况很少见，但在这种情况下应考虑到阑尾。
